1. Field of the Invention
The present invention relates to a method of semiconductor chip cooling. The invention further provides for an arrangement to improve the cooling capability of semiconductor chips, as well as the requisite mechanical structure to achieve an efficient degree of cooling.
A problem which is prevalent in the electronics industry, resides in the difficulties encountered in transferring heat generated from a semiconductor chip to a heat sink arrangement or device for cooling of the semiconductor chip. The presently encountered increase in semiconductor chip power and power density are frequently accompanied by a rise in the thermal resistance between the semiconductor chip and a heat sink device. The prevalent traditional employment of a thermal grease may readily reach its maximum upper limit to provide a low thermal resistance, which is demanded because of its low thermal conductivity and the requirement for providing a close-fitted mechanical structure so as to ensure a satisfactory performance thereof. An improved semiconductor chip thermal interface, as well as a superior mechanical interface between the semiconductor chip and its heat sink device while subjecting the chip to only a low mechanical stress, is therefore a need which must be met in the technology.
2. Discussion of the Prior Art
Currently, various publications are directed to solving of the problems encountered in transferring heat from heat-generating components to heat sink structures through the employment of diverse heat conveying and spreading methods of which the following are representative.
Saaski, et al., U.S. Pat. No. 4,833,567, disclose a method of placing electronic components inside an integral heat pipe which consists of a condenser cap mounted on a substrate in order to form a sealed pipe chamber. Multi-layered wicks are placed between the condenser and the electronic components, so as to facilitate the transfer of heat away from the electronic components.
Shanker, et al., U.S. Pat. No. 4,912,548, are concerned with a method of inserting a heat pipe through the lid of a semiconductor-chip housing whereby the heat pipe terminates within the housing cavity at the hot end of the heat pipe, and enables the transfer of heat to a cold end thereof.
Saito, et al., U.S. Pat. No. 4,796,155, teach a method of housing a solid state device inside a coolant vessel containing a liquid coolant with the presence of a vapor space, and which is adapted to provide a coolant vapor to cool the solid state device.
Wiech Jr., U.S. Pat. No. 4,519,447, discloses two methods for cooling a substrate, one method employing a flat vapor chamber for heat spreading, and the other method utilizing a magnetohydrodynamically-driven liquid cooling plate to form a heat transferring path for cooling the substrate.